1. Field of the Invention
This invention is directed to drilling oil and gas wellbores in the earth; in certain particular aspects, to drilling and completing such multiple wellbores from a single drilling rig; and, in certain particular aspects, to drilling and completing such multiple wellbores so that they are relatively close to each other.
2. Description of Related Art
A wide variety of drilling rigs and methods are known for drilling oil and gas wellbores in the earth. In many known systems and methods, a single wellbore is drilled with a drilling rig and then, to drill another wellbore, the drilling rig is moved to a new location, often near the drilled wellbore. By way of example only (and not as a definitive or exhaustive disclosure) the following U.S. Patents and Application disclose drilling rigs and/or methods of the use of rigs (all incorporated fully herein for all purposes): U.S. Pat. Nos. 2,840,198; 4,108,255; 4,616,454; 6,068,069; 6,161,358; 6,443,240; 6,766,860 and Application No. 2007/0251725A1.
Many patents and publications illustrate and describe in detail known drilling rigs. By way of example only (and not as a definitive or exhaustive disclosure), U.S. Pat. No. 7,320,374 discloses systems and methods as shown in FIGS. 1A and 1B in which a known top drive system TDS1 in a derrick 140 is suspended from a block becket 18 which is suspended from the derrick 140 in a typical manner. A standard block and hook for hooking a standard becket may be used. An elevator 74 supports a tubular stand 142 which includes two pieces (or three) of drill pipe 143. The stand 142 has been moved from a monkey board 145 with multiple made-up stands 149 to a position axially aligned with a wellbore 147. A mouse hole 144 may be used, e.g. to make stands. A driller controls drilling from a driller's panel 141. The stands 149 are located at a setback position ST. Optionally, the system includes an emergency brake system and/or an emergency shut down device and, optionally, either or both are controllable from the panel 141.
Also by way of example only, as shown in FIG. 2 U.S. Pat. No. 5,107,940 discloses a known system TDS2 which includes a power swivel 30 and guide mechanism 51 mounted on a mast 102 of a conventional portable rotary earth drilling rig generally designated by the numeral 100. As will hereinafter be more fully explained, the power swivel 30 is pivotally secured through a floating torque arm assembly, called a carriage 70, to a pair of dollies 75 movable longitudinally on a guide track 51 mounted on the mast 102. The guide mechanism 51 illustrated in FIGS. 7-9, and the carriage 70, illustrated in FIGS. 10 and 11 of the drawings, form a torque restraint system.
The drilling rig 100 is a conventional 118 foot vehicle-mounted hydraulically telescoping derrick, having an inclined mast 102 with a hook load capacity of, for example 365,000 pounds. The mast 102 is typically inclined at a lean angle 119 of 3½ degrees relative to a vertical axis 125 centered over the well.
The mast 102 is pivotally mounted on a trailer 104 and is transported in a horizontal position with the upper mast section 115 telescoped into the lower mast section 110. When the mast 102 is erected, the telescoped sections 110 and 115 are rotated approximately 90 degrees about a horizontal axis to a vertical position by hydraulically-actuated rams 106. After legs on the lower mast section 110 engage the ground or other supporting surface, hydraulic fluid is delivered to hydraulically-actuated cylinders which raise the upper mast section 115 to the position illustrated in FIG. 1, wherein only the lower end of the upper section 115 extends downwardly into the upper end of the lower section 110.
The trailer-mounted rig includes a single drum drawworks 105 powered by diesel engines 103 through conventional transmissions and a compound box. A fast line 107 extends from drawworks 105 upwardly over a crown block 108, as illustrated in FIG. 1, to provide a number of lines 109 which carry a traveling block 112 connected to the power swivel 30 in the top drive system 20. A conventional folding substructure 140, equipped with a V-door 142, a catwalk 145, and two sets of pipe racks (not shown), parallel and juxtaposed to the catwalk, are mounted adjacent to the inclined telescoping mast 102.
The stand assembly system consists of a crown cantilevered single joint elevator snatch block 21 mounted directly over the mouse hole, an auxiliary cable 22, a live swivel assembly 23 and a single joint elevator 148. The system is permanently installed in the rig for use at any time.
The auxiliary cable 22 is designed to quickly attach to existing hydraulic or pneumatically-powered auxiliary tugger lines and is used to hoist a single joint 24′ from the pipe ramp to the mouse hole, and to hoist a complete stand 25 from the mouse hole to the fingerboard 136 and set the stand 25 back on the setback SK.
The single joint elevator 148 is a specially-designed elevator with, for example, a 2,000 pound hoisting capacity for quick attachment to and release from the drill pipe. It is attached to the auxiliary cable 22 utilizing a live swivel assembly 23 to prevent upspiraling of the cable while shouldering up a stand 25 in the mouse hole.
During operation, a stand 25 is attached to or removed from the drill string 150, utilizing elevator 48.
The guide track 51 is rigid and continuous; it extends longitudinally along mast 102. The guide track 51 is formed in at least two segments: a lower guide track segment 52, and an upper guide track segment 54, secured to the lower mast segment 110 and upper mast segment 120 115, respectively (see FIG. 1). The guide track 51 shown can be comprised of, for example 3½ inch standard pipe sections, each approximately 20 feet long (for easy handling). However, it should be appreciated that guide track 51 may be formed of members having non-circular cross-sections, such as H-beams, without departing from the basic concept of the torque restraint system.
FIGS. 13-15 of U.S. Pat. No. 5,107,940 describe the procedure for making up a stand 25. FIGS. 16-18 of U.S. Pat. No. 5,107,940 describe how a made-up stand is added to a drilling string.
U.S. Pat. No. 4,108,255 discloses an apparatus for drilling concurrently a plurality of wells within a laterally confined area. The confines of the drilling apparatus employ a structure having vertically extending walls rising from a drilling floor. A plurality of wells are drilled, each employing a separate rotary drilling table and a separate draw work assembly mounted in vertical displacement from the drilling table associated there with. Preferably, the individual draw work assemblies associated with separate rotary drilling tables are utilized only to feed drilling pipe assemblies into the well and to aid in the actual drilling operation. To withdraw drilling pipe assemblies, a master draw works is provided and is mounted vertically above the draw work assemblies associated with particular rotary drilling tables. In addition, the draw work assemblies are preferably located on bridges which are rotatably mounted with respect to an upright central support, so that the bridges are rotatable about the upright support and carriages forming part of the draw works are movable along the bridges so that the carriages may be moved both radially and rotationally relative to the upright support. The confining structure of the vertically extending walls renders the well drilling apparatus suitable for construction for use in drilling wells on the floor of a body of water and also for use in drilling a plurality of wells in a highly urbanized areas. This versatility is achieved by constructing the well drilling apparatus with exterior walls of the confining structure in the form of a facade, to resemble a commercial building or in the form of a water resistant cassion that may be lowered into a body of water to extend from the floor to the surface thereof. In one aspect this patent discloses a well drilling apparatus located within a confining structure having cylindrical annular vertically extending walls rising from a drilling floor and enclosing: a plurality of rotary drilling tables laterally displaced from each other proximate to said drilling floor and within the confines of said walls each arranged to accommodate separate drilling assemblies including drilling pipe for drilling separate wells at spatially separated locations at said drilling floor; an upright support extending upward relative to the drilling floor within said confining structure; and separate drilling draw work assemblies associated with and mounted in vertical displacement from each of said rotary drilling tables for manipulating the drilling pipe and other portions of the drilling assembly utilized with the associated rotary table, wherein each of said separate drilling draw work assemblies is mounted on a separate bridge that extends laterally from said upright support and is supported at said vertically extending walls at a distance above the rotary drilling table with which it is associated.
In several situations it is desirable to drill wellbores for oil and gas wells relatively near to each other, e.g. within 8 to 12 feet of each other (or more) (platforms are often within 16 to 32 feet of each other). A variety of problems and disadvantages are associated with certain typical ways for drilling wellbores that are close to each other. Often, using rigs designed for drilling one hole and then moving the rig to drill another hole, much of the total time expended to drill multiple holes is not time spent actually drilling.